drivers/serial/serial_ns16550.c - barebox/mindspeed - Git at Google

 /**
  * @file
  * @brief NS16550 Driver implementation
  *
  * FileName: drivers/serial/serial_ns16550.c
  *
  * NS16550 support
  * Modified from u-boot drivers/serial.c and drivers/ns16550.c
  * originally from linux source (arch/ppc/boot/ns16550.c)
  * modified to use CFG_ISA_MEM and new defines
  */
 /*
  * (C) Copyright 2008
  * Texas Instruments, <www.ti.com>
  * Nishanth Menon <x0nishan@ti.com>
  *
  * (C) Copyright 2000
  * Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
  *
  * See file CREDITS for list of people who contributed to this
  * project.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation; either version 2 of
  * the License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  * MA 02111-1307 USA
  */

 #include <common.h>
 #include <driver.h>
 #include <init.h>
 #include <errno.h>
 #include <malloc.h>
 #include <asm/io.h>

 #include "serial_ns16550.h"
 #include <ns16550.h>

 /*********** Private Functions **********************************/

 /**
  * @brief Compute the divisor for a baud rate
  *
  * @param[in] cdev pointer to console device
  * @param[in] baudrate baud rate
  *
  * @return divisor to be set
  */
 static unsigned int ns16550_calc_divisor(struct console_device *cdev,
 					 unsigned int baudrate)
 {
 	struct NS16550_plat *plat = (struct NS16550_plat *)
 	    cdev->dev->platform_data;
 	unsigned int clk = plat->clock;
 #ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
 	/* FIXME: Legacy Code copied from U-Boot V1 implementation
 	 */
 #ifdef CONFIG_ARCH_OMAP1510
 	unsigned long base = cdev->dev->map_base;
 	/* If can't cleanly clock 115200 set div to 1 */
 	if ((clk == 12000000) && (baudrate == 115200)) {
 		/* enable 6.5 * divisor */
 		plat->reg_write(OSC_12M_SEL, base, osc_12m_sel);
 		return 1;	/* return 1 for base divisor */
 	}
 	/* clear if previously set */
 	plat->reg_write(0, base, osc_12m_sel);
 #elif defined(CONFIG_ARCH_OMAP1610)
 	/* If can't cleanly clock 115200 set div to 1 */
 	if ((clk == 48000000) && (baudrate == 115200))
 		return 26;	/* return 26 for base divisor */
 #endif

 #endif				/* End of OMAP specific handling */
 	return (clk / MODE_X_DIV / baudrate);

 }

 /**
  * @brief Initialize the device
  *
  * @param[in] cdev pointer to console device
  */
 static void ns16550_serial_init_port(struct console_device *cdev)
 {
 	struct NS16550_plat *plat = (struct NS16550_plat *)
 	    cdev->dev->platform_data;
 	unsigned long base = cdev->dev->map_base;
 	unsigned int baud_divisor;

 	/* Setup the serial port with the defaults first */
 	baud_divisor = ns16550_calc_divisor(cdev, CONFIG_BAUDRATE);

 	/* initializing the device for the first time */
 	plat->reg_write(0x00, base, ier);
 #ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
 	plat->reg_write(0x07, base, mdr1);	/* Disable */
 #endif
 	plat->reg_write(LCR_BKSE | LCRVAL, base, lcr);
 	plat->reg_write(baud_divisor & 0xFF, base, dll);
 	plat->reg_write((baud_divisor >> 8) & 0xff, base, dlm);
 	plat->reg_write(LCRVAL, base, lcr);
 	plat->reg_write(MCRVAL, base, mcr);
 	plat->reg_write(FCRVAL, base, fcr);
 #ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
 	plat->reg_write(0x00, base, mdr1);
 #endif
 }

 /*********** Exposed Functions **********************************/

 /**
  * @brief Put a character to the serial port
  *
  * @param[in] cdev pointer to console device
  * @param[in] c character to put
  */
 static void ns16550_putc(struct console_device *cdev, char c)
 {
 	struct NS16550_plat *plat = (struct NS16550_plat *)
 	    cdev->dev->platform_data;
 	unsigned long base = cdev->dev->map_base;
 	/* Loop Doing Nothing */
 	while ((plat->reg_read(base, lsr) & LSR_THRE) == 0) ;
 	plat->reg_write(c, base, thr);
 }

 /**
  * @brief Retrieve a character from serial port
  *
  * @param[in] cdev pointer to console device
  *
  * @return return the character read
  */
 static int ns16550_getc(struct console_device *cdev)
 {
 	struct NS16550_plat *plat = (struct NS16550_plat *)
 	    cdev->dev->platform_data;
 	unsigned long base = cdev->dev->map_base;
 	/* Loop Doing Nothing */
 	while ((plat->reg_read(base, lsr) & LSR_DR) == 0) ;
 	return plat->reg_read(base, rbr);
 }

 /**
  * @brief Test if character is available
  *
  * @param[in] cdev pointer to console device
  *
  * @return  - status based on data availability
  */
 static int ns16550_tstc(struct console_device *cdev)
 {
 	struct NS16550_plat *plat = (struct NS16550_plat *)
 	    cdev->dev->platform_data;
 	unsigned long base = cdev->dev->map_base;
 	return ((plat->reg_read(base, lsr) & LSR_DR) != 0);
 }

 /**
  * @brief Set the baudrate for the uart port
  *
  * @param[in] cdev  console device
  * @param[in] baud_rate baud rate to set
  *
  * @return  0-implied to support the baudrate
  */
 static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
 {
 	struct NS16550_plat *plat = (struct NS16550_plat *)
 	    cdev->dev->platform_data;
 	unsigned long base = cdev->dev->map_base;
 	unsigned int baud_divisor = ns16550_calc_divisor(cdev, baud_rate);
 	plat->reg_write(0x00, base, ier);
 	plat->reg_write(LCR_BKSE, base, lcr);
 	plat->reg_write(baud_divisor & 0xff, base, dll);
 	plat->reg_write((baud_divisor >> 8) & 0xff, base, dlm);
 	plat->reg_write(LCRVAL, base, lcr);
 	plat->reg_write(MCRVAL, base, mcr);
 	plat->reg_write(FCRVAL, base, fcr);
 	return 0;
 }

 /**
  * @brief Probe entry point -called on the first match for device
  *
  * @param[in] dev matched device
  *
  * @return EINVAL if platform_data is not populated,
  *	   ENOMEM if calloc failed
  *	   else return result of console_register
  */
 static int ns16550_probe(struct device_d *dev)
 {
 	struct console_device *cdev;
 	struct NS16550_plat *plat = (struct NS16550_plat *)dev->platform_data;

 	/* we do expect platform specific data */
 	if (plat == NULL)
 		return -EINVAL;
 	if ((plat->reg_read == NULL) || (plat->reg_write == NULL))
 		return -EINVAL;

 	cdev = xzalloc(sizeof(*cdev));

 	dev->type_data = cdev;
 	cdev->dev = dev;
 	cdev->f_caps = plat->f_caps;
 	cdev->tstc = ns16550_tstc;
 	cdev->putc = ns16550_putc;
 	cdev->getc = ns16550_getc;
 	cdev->setbrg = ns16550_setbaudrate;

 	ns16550_serial_init_port(cdev);

 	return console_register(cdev);
 }

 /**
  * @brief Driver registration structure
  */
 static struct driver_d ns16550_serial_driver = {
 	.name = "serial_ns16550",
 	.probe = ns16550_probe,
 };

 /**
  * @brief driver initialization function
  *
  * @return result of register_driver
  */
 static int ns16550_serial_init(void)
 {
 	return register_driver(&ns16550_serial_driver);
 }

 console_initcall(ns16550_serial_init);
	/**
	* @file
	* @brief NS16550 Driver implementation
	*
	* FileName: drivers/serial/serial_ns16550.c
	*
	* NS16550 support
	* Modified from u-boot drivers/serial.c and drivers/ns16550.c
	* originally from linux source (arch/ppc/boot/ns16550.c)
	* modified to use CFG_ISA_MEM and new defines
	*/
	/*
	* (C) Copyright 2008
	* Texas Instruments, <www.ti.com>
	* Nishanth Menon <x0nishan@ti.com>
	*
	* (C) Copyright 2000
	* Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
	*
	* See file CREDITS for list of people who contributed to this
	* project.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License as
	* published by the Free Software Foundation; either version 2 of
	* the License, or (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	* MA 02111-1307 USA
	*/

	#include <common.h>
	#include <driver.h>
	#include <init.h>
	#include <errno.h>
	#include <malloc.h>
	#include <asm/io.h>

	#include "serial_ns16550.h"
	#include <ns16550.h>

	/********* Private Functions ********************************/

	/**
	* @brief Compute the divisor for a baud rate
	*
	* @param[in] cdev pointer to console device
	* @param[in] baudrate baud rate
	*
	* @return divisor to be set
	*/
	static unsigned int ns16550_calc_divisor(struct console_device *cdev,
	unsigned int baudrate)
	{
	struct NS16550_plat plat = (struct NS16550_plat )
	cdev->dev->platform_data;
	unsigned int clk = plat->clock;
	#ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
	/* FIXME: Legacy Code copied from U-Boot V1 implementation
	*/
	#ifdef CONFIG_ARCH_OMAP1510
	unsigned long base = cdev->dev->map_base;
	/* If can't cleanly clock 115200 set div to 1 */
	if ((clk == 12000000) && (baudrate == 115200)) {
	/* enable 6.5 * divisor */
	plat->reg_write(OSC_12M_SEL, base, osc_12m_sel);
	return 1; /* return 1 for base divisor */
	}
	/* clear if previously set */
	plat->reg_write(0, base, osc_12m_sel);
	#elif defined(CONFIG_ARCH_OMAP1610)
	/* If can't cleanly clock 115200 set div to 1 */
	if ((clk == 48000000) && (baudrate == 115200))
	return 26; /* return 26 for base divisor */
	#endif

	#endif /* End of OMAP specific handling */
	return (clk / MODE_X_DIV / baudrate);

	}

	/**
	* @brief Initialize the device
	*
	* @param[in] cdev pointer to console device
	*/
	static void ns16550_serial_init_port(struct console_device *cdev)
	{
	struct NS16550_plat plat = (struct NS16550_plat )
	cdev->dev->platform_data;
	unsigned long base = cdev->dev->map_base;
	unsigned int baud_divisor;

	/* Setup the serial port with the defaults first */
	baud_divisor = ns16550_calc_divisor(cdev, CONFIG_BAUDRATE);

	/* initializing the device for the first time */
	plat->reg_write(0x00, base, ier);
	#ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
	plat->reg_write(0x07, base, mdr1); /* Disable */
	#endif
	plat->reg_write(LCR_BKSE \| LCRVAL, base, lcr);
	plat->reg_write(baud_divisor & 0xFF, base, dll);
	plat->reg_write((baud_divisor >> 8) & 0xff, base, dlm);
	plat->reg_write(LCRVAL, base, lcr);
	plat->reg_write(MCRVAL, base, mcr);
	plat->reg_write(FCRVAL, base, fcr);
	#ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
	plat->reg_write(0x00, base, mdr1);
	#endif
	}

	/********* Exposed Functions ********************************/

	/**
	* @brief Put a character to the serial port
	*
	* @param[in] cdev pointer to console device
	* @param[in] c character to put
	*/
	static void ns16550_putc(struct console_device *cdev, char c)
	{
	struct NS16550_plat plat = (struct NS16550_plat )
	cdev->dev->platform_data;
	unsigned long base = cdev->dev->map_base;
	/* Loop Doing Nothing */
	while ((plat->reg_read(base, lsr) & LSR_THRE) == 0) ;
	plat->reg_write(c, base, thr);
	}

	/**
	* @brief Retrieve a character from serial port
	*
	* @param[in] cdev pointer to console device
	*
	* @return return the character read
	*/
	static int ns16550_getc(struct console_device *cdev)
	{
	struct NS16550_plat plat = (struct NS16550_plat )
	cdev->dev->platform_data;
	unsigned long base = cdev->dev->map_base;
	/* Loop Doing Nothing */
	while ((plat->reg_read(base, lsr) & LSR_DR) == 0) ;
	return plat->reg_read(base, rbr);
	}

	/**
	* @brief Test if character is available
	*
	* @param[in] cdev pointer to console device
	*
	* @return - status based on data availability
	*/
	static int ns16550_tstc(struct console_device *cdev)
	{
	struct NS16550_plat plat = (struct NS16550_plat )
	cdev->dev->platform_data;
	unsigned long base = cdev->dev->map_base;
	return ((plat->reg_read(base, lsr) & LSR_DR) != 0);
	}

	/**
	* @brief Set the baudrate for the uart port
	*
	* @param[in] cdev console device
	* @param[in] baud_rate baud rate to set
	*
	* @return 0-implied to support the baudrate
	*/
	static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
	{
	struct NS16550_plat plat = (struct NS16550_plat )
	cdev->dev->platform_data;
	unsigned long base = cdev->dev->map_base;
	unsigned int baud_divisor = ns16550_calc_divisor(cdev, baud_rate);
	plat->reg_write(0x00, base, ier);
	plat->reg_write(LCR_BKSE, base, lcr);
	plat->reg_write(baud_divisor & 0xff, base, dll);
	plat->reg_write((baud_divisor >> 8) & 0xff, base, dlm);
	plat->reg_write(LCRVAL, base, lcr);
	plat->reg_write(MCRVAL, base, mcr);
	plat->reg_write(FCRVAL, base, fcr);
	return 0;
	}

	/**
	* @brief Probe entry point -called on the first match for device
	*
	* @param[in] dev matched device
	*
	* @return EINVAL if platform_data is not populated,
	* ENOMEM if calloc failed
	* else return result of console_register
	*/
	static int ns16550_probe(struct device_d *dev)
	{
	struct console_device *cdev;
	struct NS16550_plat plat = (struct NS16550_plat )dev->platform_data;

	/* we do expect platform specific data */
	if (plat == NULL)
	return -EINVAL;
	if ((plat->reg_read == NULL) \|\| (plat->reg_write == NULL))
	return -EINVAL;

	cdev = xzalloc(sizeof(*cdev));

	dev->type_data = cdev;
	cdev->dev = dev;
	cdev->f_caps = plat->f_caps;
	cdev->tstc = ns16550_tstc;
	cdev->putc = ns16550_putc;
	cdev->getc = ns16550_getc;
	cdev->setbrg = ns16550_setbaudrate;

	ns16550_serial_init_port(cdev);

	return console_register(cdev);
	}

	/**
	* @brief Driver registration structure
	*/
	static struct driver_d ns16550_serial_driver = {
	.name = "serial_ns16550",
	.probe = ns16550_probe,
	};

	/**
	* @brief driver initialization function
	*
	* @return result of register_driver
	*/
	static int ns16550_serial_init(void)
	{
	return register_driver(&ns16550_serial_driver);
	}

	console_initcall(ns16550_serial_init);